Posts for the month of May 2020

Update: ARCHER return to service - UM work flow

We continue to work with ARCHER to implement a robust solution to handle the 2FA access. Until we have that solution, this is a short-term alternative. In your PUMA or pumatest .ssh/config file, delete references to login.archer.ac.uk and then add:

Host login.archer.ac.uk
User <your ARCHER username>
IdentityFile ~/.ssh/<your private key to ARCHER>
ControlMaster auto
ControlPath /tmp/ssh-socket-%r@%h-%p
ControlPersist yes

login to ARCHER (with passphrase and password).

Rose/Cylc suites should not use rose host-select - it will not work; suites must specify login.archer.ac.uk in the appropriate .rc file (suite.rc or archer.rc), for example, host = login.archer.ac.uk

Submit UMUI and Rose/Cylc jobs as usual.

The connection to ARCHER will persist after logging out of PUMA/pumatest and will enable the Cylc engine to manage your suite. However, the connection will be terminated (each day at ~5AM in our experience) - logging in to ARCHER will re-establish the connection and Rose/Cylc suites will pick up automatically. If a suite times out (over a weekend possibly), a normal rose suite-restart should get it going again.

ARCHER return to service - UM work flow

When ARCHER returns to operation on May 21st all users will be required to use two credentials to access the service: an SSH key with a passphrase and their ARCHER password.

Rose/Cylc suites and UMUI jobs will not run under this HPC access model. We are working closely with ARCHER to develop and implement a solution that will enable UM work flows to function with the new security scheme.